1. Changing the living world

3. Selective Breeding Humans use selective breeding to pass desired traits on to the next generation of organisms: Nearly all domestic animals and most crop plants have been produced by selective breeding

4. Tools for selective breeding Hybridization: crossing dissimilar individuals to bring together the best of both organisms -e.g. Shasta daisies, got its large, white appearance from hybridization by a scientist named Luther Burbank Inbreeding: the continued breeding of individuals with similar characteristics -e.g. Many breeds of dogs are maintained by inbreeding: golden retriever

5. Risk of inbreeding Most of the members of a breed are genetically similar: -Because of this, there is always a chance that a cross between two individuals will bring together 2 recessive alleles for a genetic defect

6. Increasing Variability Breeders can increase the genetic variation in a population by inducing mutations, which are the ultimate source of genetic variability Breeders can increase the mutation rate by using radiation and chemicals

7. Increasing Variation Producing new kinds of bacteria: scientists have been able to develop hundreds of useful bacteria strains e.g. bacteria that can digest oil Producing new kinds of plants: scientists use drugs to produce cells that have double or triple the normal number of chromosomes (polyploid) e.g. production of bananas